CVE-2025-43189 is a critical vulnerability in Apple macOS that allows a malicious application to read kernel memory. The vulnerability arises from improper memory handling within the macOS kernel, which is the core component responsible for managing system resources and enforcing security boundaries. Exploiting this flaw, an attacker can gain unauthorized access to sensitive kernel memory contents, potentially exposing confidential data, including cryptographic keys, passwords, or other protected information. The vulnerability has a CVSS score of 9.8, indicating a critical severity level, with an attack vector that is network accessible (AV:N), requiring no privileges (PR:N) and no user interaction (UI:N). The scope is unchanged (S:U), but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). This means the attacker can fully compromise the system's security posture by reading kernel memory, potentially leading to privilege escalation, system compromise, or denial of service. The issue was addressed by Apple through improved memory handling and fixed in macOS Sequoia 15.6 and macOS Sonoma 14.7.7. No known exploits are currently reported in the wild, but the critical nature and ease of exploitation make it a significant threat. The vulnerability is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor).

For European organizations, this vulnerability poses a severe risk, especially those relying on macOS systems for critical operations, including government agencies, financial institutions, technology firms, and research entities. The ability for a malicious app to read kernel memory without requiring user interaction or privileges means that supply chain attacks, malicious insider apps, or drive-by downloads could lead to significant data breaches. Confidential information such as encryption keys, user credentials, and proprietary data could be exposed, undermining data privacy and regulatory compliance (e.g., GDPR). Furthermore, the potential for system integrity compromise and availability disruption could affect business continuity and operational reliability. Given the criticality, organizations with macOS endpoints must prioritize patching to prevent exploitation that could lead to widespread compromise or targeted attacks against sensitive infrastructure.

European organizations should immediately verify the macOS versions in use and prioritize upgrading to macOS Sequoia 15.6 or macOS Sonoma 14.7.7 or later, where the vulnerability is patched. Beyond patching, organizations should implement strict application control policies to limit the installation and execution of untrusted or unsigned applications, reducing the risk of malicious apps exploiting this vulnerability. Employ endpoint detection and response (EDR) solutions capable of monitoring kernel-level activities and anomalous memory access patterns. Network segmentation and least privilege principles should be enforced to minimize the attack surface. Additionally, organizations should conduct regular security audits and vulnerability assessments on macOS systems, ensuring compliance with security baselines. User awareness training should emphasize the risks of installing unauthorized software. For environments where immediate patching is not feasible, consider disabling or restricting features that allow third-party apps to interact with kernel components, if possible, as a temporary mitigation.